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CSharp · Console

/Program.cs

using System;
using System.Text.RegularExpressions;
					
public class Program
{
	public static void Main()
	{
		string convert = "4+18/(9-3)";

        MatchCollection parts = Regex.Matches(convert, @"([\d\.]+|[()e^/%x*+-])");
		
		foreach(Match p in parts)
			Console.WriteLine("\"" + p.Value + "\"");
	}
}